Muscle Tissue & Basic Muscle Anatomy

1. Muscle Tissue & Basic Muscle Anatomy p. 178-184 NOTE: Myo-, mys-, & sarco- : All refer to muscle!

2. 3 Muscle Tissue Types

3. Smooth Muscle • Often arranged in two perpendicular layers

4. Cardiac Muscle • Important that all cells contract at once • Bundles of cells arranged in spiral / figure-8 patterns • Branching cells • Intercalated discs – join cells

5. Skeletal Muscle • Makes up the muscular system • Muscles exert tremendous force • Wrapped in layers of dense connective tissue to hold them together

6. Functions of the Muscular System • Produces movement • Maintains posture • Stabilizes joints • Generates heat • Byproduct of using ATP (energy) for skeletal muscle contraction

7. Skeletal Muscle Tissue • Muscle cell = muscle fiber • Specialized to contract • Cells are bundled together to form fascicles • Connective tissue wrappings: • Endomysium • Perimysium • Epimysium • Continuous with tendons and aponeuroses

8. Tendons • Structure: • Dense connective tissue (collagen fibers) • Functions: • Attach muscles to bone, cartilage, or connective tissue coverings • Conserve space across joints • Durable enough to cross rough bony projections

9. Aponeuroses

10. Muscle Fascicles Muscle Fibers Myofibrils Myofilaments • Myofibrils • Myofilaments

11. Sarcomere– functional unit of muscle

12. Myofilaments • Actin (thin filaments) • Myosin (thick filaments) • Myosin heads • Form cross-bridges with actin • Z discs

13. Striations • Light (I) bands • Dark (A) bands